Jmf spectra chorus/reverb problem

[WhydidIbuythisthing?]

Hello all. Hope your day is going as good as it is when you find that great deal. Do any of you know how to repair the Chorus and reverb on a spectra 180.. The foot switch works. But, the chorus will not turn on and reverb will not turn off. Distortion works fine.
I bought one because it was the first amp I ever had when I first started playing guitar. I cleaned the electronics and it sounds great. Such a unique sound compared to most amps. Very nice clean, and mild drive.
Any advice will be greatly appreciated. Either way. Have a great day!!

[Chuck H]

I don't know these amps but I think a default mode, that is 'no footswitch plugged in' would be reverb on and chorus off. So it's possible whatever switch triggers are in the amp for the reverb and chorus are not responding (check supply voltage for any switching transistors) or the there is a problem with the foot switch connecor at the amp. Hard to say otherwise becuase shematics for old JMF Spectra amps are rare as hens teeth. Even the later Dean Markley era amps no longer have an on line schematic library since Dean sold his company and they changed the website. I think this will be impossible without a schematic. I was unable to find one with normal, shallow searches.

Here's a link to someone with a similar problem but the schematic is illegible:

https://music-electronics-forum.com/...ey-spectra-225

[WhydidIbuythisthing?]

Thank you for your reply. I will start with what you suggested. I will try to find schematic. I am a beginner when it comes to trouble shooting. But I know enough to keep myself safe. Thank you!!

[WhydidIbuythisthing?]

Anyone else ever run into this before? The amp sounds absolutely incredible. It has massive dynamics. If you ever get a chance to play one try it. Had to clean pots and jacks, then use a electronic lubricant. But very nice amp.

[Chuck H]

Nothing new on the matter. Just wanted to mention that the later tube amps built by JMF Spectra for DMS are generally liked and even enjoy a small cult following. I got to play with a couple when I worked with Dean and they were very useful and musical amps. Look at what Kustom and Roland were able to do with SS ams! The JMF Spectra SS amps were following in those footsteps and I'm sure they were better than anyone would expect, as you've reported.

Short of a schematic another (more expensive) option would be to take the amp to a service tech. With the amp on the bench it would be a lot easier to diagnose for a pro. Without a readable schematic that may be the only option.

[WhydidIbuythisthing?]

Ok. Thank you. The foot switch will turn it off and on as far as the light. And the pots adjust the rate. I can see the light flashing faster or slower when I turn the pot. I will find a repair tech. I am not qualified to trouble shoot. With guidance I can fix the problem. Thank you for you help. I didn't buy the amp for anything but nostalgia. After 30 plus years of playing I can make a gorilla amp sound decent. I just didn't realize the dynamic response they had until a few days ago. Thanks!!